In electrostatographic printing and photocopy machines in which the toner image is transferred from the transfer member to the image receiving substrate, it is desired that the transfer of the toner particles from the transfer member to the image receiving substrate be substantially 100 percent. Less than complete transfer to the image receiving substrate results in image degradation and low resolution. Complete transfer is particularly desirable when the imaging process involves generating full color images since undesirable color deterioration in the final colors may occur when the color images are not completely transferred from the transfer member.
However, in the electrostatic transfer applications, the use of seamed intermediate transfer belts results in insufficient transfer in that the developed image occurring on the seam is not adequately transferred. This incomplete transfer is partially the result of the difference in seam height to the rest of the intermediate transfer belt. A “bump” is formed at the seam, thereby hindering transfer and mechanical performance. A bump in the intermediate transfer belt may also introduce poor motion quality into the system as it passes various elements such as cleaning blades, roller nips, and others.
U.S. application Ser. No. 12/550,486, which issued as U.S. Pat. No. 8,084,112 to Wu et al. proposes applying an overcoat to an intermediate transfer belt substrate, which functionally masks the appearance of the imageable seam. Although print test results demonstrate the ability of the overcoat to mask the imageable seam and improve imageability of the seam, inferior adhesion of the overcoat to the intermediate transfer member substrate has been observed, resulting in a significant obstacle to application of overcoat technology to an intermediate transfer member substrate. The present disclosure addresses the problem of inferior adhesion of an overcoat to the intermediate transfer member substrate, after applying an imageable seam overcoat to an intermediate transfer member substrate.
In order to significantly improve adhesion of an imageable seam overcoat to the intermediate transfer member substrate, the present disclosure provides a process for applying a corona pretreatment process to an intermediate transfer member substrate to modify the surface characteristics of the intermediate transfer member substrate prior to applying the imageable seam overcoat, thereby improving the overcoat adhesion at the interface of the overcoat and the intermediate transfer member substrate. This corona treatment process effectively eliminates the need for a separate adhesive or primer layer to aid adhesion of the imageable seam overcoat and the intermediate transfer member substrate.
The corona treatment process may be applied while the intermediate transfer member substrate material is in roll form or belt form. If the intermediate transfer member substrate material is in roll form, then the corona treatment apparatus may include a fixture having an unwind or rewind functionality, a web guide system, and a corona generation apparatus. The corona generation apparatus may include a high voltage power supply, an electrode, and a ground roll or plate. Similarly, if the intermediate transfer member substrate material is in belt form, then the corona treatment apparatus may include an actively steered belt cycling fixture, which contains the aforementioned corona generation apparatus.
Various corona discharge methods are known. U.S. Pat. No. 6,528,226 describes the application of plasma treatment to a photoreceptor. The appropriate components and process aspects of the foregoing patent publication may be selected for the present disclosure in embodiments thereof, and the entire disclosure of the above-mentioned reference is totally incorporated herein by reference.